linux find文档

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find文档

[root@rockylinux shell]# man find

FIND(1) General Commands Manual FIND(1)

NAME
find - search for files in a directory hierarchy

SYNOPSIS
find [-H] [-L] [-P] [-D debugopts] [-Olevel] [starting-point...] [expression]

DESCRIPTION
This manual page documents the GNU version of find. GNU find searches the direc‐
tory tree rooted at each given starting-point by evaluating the given expression
from left to right, according to the rules of precedence (see section OPERATORS),
until the outcome is known (the left hand side is false for and operations, true
for or), at which point find moves on to the next file name. If no starting-point
is specified, `.' is assumed.

If you are using find in an environment where security is important (for example if
you are using it to search directories that are writable by other users), you
should read the "Security Considerations" chapter of the findutils documentation,
which is called Finding Files and comes with findutils. That document also
includes a lot more detail and discussion than this manual page, so you may find it
a more useful source of information.

OPTIONS
The -H, -L and -P options control the treatment of symbolic links. Command-line
arguments following these are taken to be names of files or directories to be exam‐
ined, up to the first argument that begins with `-', or the argument `(' or `!'.
That argument and any following arguments are taken to be the expression describing
what is to be searched for. If no paths are given, the current directory is used.
If no expression is given, the expression -print is used (but you should probably
consider using -print0 instead, anyway).

This manual page talks about `options' within the expression list. These options
control the behaviour of find but are specified immediately after the last path
name. The five `real' options -H, -L, -P, -D and -O must appear before the first
path name, if at all. A double dash -- can also be used to signal that any remain‐
ing arguments are not options (though ensuring that all start points begin with
either `./' or `/' is generally safer if you use wildcards in the list of start
points).

-P Never follow symbolic links. This is the default behaviour. When find
examines or prints information a file, and the file is a symbolic link, the
information used shall be taken from the properties of the symbolic link
itself.

-L Follow symbolic links. When find examines or prints information about
files, the information used shall be taken from the properties of the file
to which the link points, not from the link itself (unless it is a broken
symbolic link or find is unable to examine the file to which the link
points). Use of this option implies -noleaf. If you later use the -P
option, -noleaf will still be in effect. If -L is in effect and find dis‐
covers a symbolic link to a subdirectory during its search, the subdirectory
pointed to by the symbolic link will be searched.

When the -L option is in effect, the -type predicate will always match
against the type of the file that a symbolic link points to rather than the
link itself (unless the symbolic link is broken). Actions that can cause
symbolic links to become broken while find is executing (for example
-delete) can give rise to confusing behaviour. Using -L causes the -lname
and -ilname predicates always to return false.

-H Do not follow symbolic links, except while processing the command line argu‐
ments. When find examines or prints information about files, the informa‐
tion used shall be taken from the properties of the symbolic link itself.
The only exception to this behaviour is when a file specified on the command
line is a symbolic link, and the link can be resolved. For that situation,
the information used is taken from whatever the link points to (that is, the
link is followed). The information about the link itself is used as a fall‐
back if the file pointed to by the symbolic link cannot be examined. If -H
is in effect and one of the paths specified on the command line is a sym‐
bolic link to a directory, the contents of that directory will be examined
(though of course -maxdepth 0 would prevent this).

If more than one of -H, -L and -P is specified, each overrides the others; the last
one appearing on the command line takes effect. Since it is the default, the -P
option should be considered to be in effect unless either -H or -L is specified.

GNU find frequently stats files during the processing of the command line itself,
before any searching has begun. These options also affect how those arguments are
processed. Specifically, there are a number of tests that compare files listed on
the command line against a file we are currently considering. In each case, the
file specified on the command line will have been examined and some of its proper‐
ties will have been saved. If the named file is in fact a symbolic link, and the
-P option is in effect (or if neither -H nor -L were specified), the information
used for the comparison will be taken from the properties of the symbolic link.
Otherwise, it will be taken from the properties of the file the link points to. If
find cannot follow the link (for example because it has insufficient privileges or
the link points to a nonexistent file) the properties of the link itself will be
used.

When the -H or -L options are in effect, any symbolic links listed as the argument
of -newer will be dereferenced, and the timestamp will be taken from the file to
which the symbolic link points. The same consideration applies to -newerXY,
-anewer and -cnewer.

The -follow option has a similar effect to -L, though it takes effect at the point
where it appears (that is, if -L is not used but -follow is, any symbolic links
appearing after -follow on the command line will be dereferenced, and those before
it will not).

-D debugoptions
Print diagnostic information; this can be helpful to diagnose problems with
why find is not doing what you want. The list of debug options should be
comma separated. Compatibility of the debug options is not guaranteed
between releases of findutils. For a complete list of valid debug options,
see the output of find -D help. Valid debug options include

help Explain the debugging options

tree Show the expression tree in its original and optimised form.

stat Print messages as files are examined with the stat and lstat system
calls. The find program tries to minimise such calls.

opt Prints diagnostic information relating to the optimisation of the
expression tree; see the -O option.

rates Prints a summary indicating how often each predicate succeeded or
failed.

-Olevel
Enables query optimisation. The find program reorders tests to speed up
execution while preserving the overall effect; that is, predicates with side
effects are not reordered relative to each other. The optimisations per‐
formed at each optimisation level are as follows.

0 Equivalent to optimisation level 1.

1 This is the default optimisation level and corresponds to the tradi‐
tional behaviour. Expressions are reordered so that tests based only
on the names of files (for example -name and -regex) are performed
first.

2 Any -type or -xtype tests are performed after any tests based only on
the names of files, but before any tests that require information
from the inode. On many modern versions of Unix, file types are
returned by readdir() and so these predicates are faster to evaluate
than predicates which need to stat the file first. If you use the
-fstype FOO predicate and specify a filesystem type FOO which is not
known (that is, present in `/etc/mtab') at the time find starts, that
predicate is equivalent to -false.

3 At this optimisation level, the full cost-based query optimiser is
enabled. The order of tests is modified so that cheap (i.e. fast)
tests are performed first and more expensive ones are performed
later, if necessary. Within each cost band, predicates are evaluated
earlier or later according to whether they are likely to succeed or
not. For -o, predicates which are likely to succeed are evaluated
earlier, and for -a, predicates which are likely to fail are evalu‐
ated earlier.

The cost-based optimiser has a fixed idea of how likely any given test is to
succeed. In some cases the probability takes account of the specific nature
of the test (for example, -type f is assumed to be more likely to succeed
than -type c). The cost-based optimiser is currently being evaluated. If
it does not actually improve the performance of find, it will be removed
again. Conversely, optimisations that prove to be reliable, robust and
effective may be enabled at lower optimisation levels over time. However,
the default behaviour (i.e. optimisation level 1) will not be changed in the
4.3.x release series. The findutils test suite runs all the tests on find
at each optimisation level and ensures that the result is the same.

EXPRESSION
The part of the command line after the list of starting points is the expression.
This is a kind of query specification describing how we match files and what we do
with the files that were matched. An expression is composed of a sequence of
things:

Tests Tests return a true or false value, usually on the basis of some property of
a file we are considering. The -empty test for example is true only when
the current file is empty.

Actions
Actions have side effects (such as printing something on the standard out‐
put) and return either true or false, usually based on whether or not they
are successful. The -print action for example prints the name of the cur‐
rent file on the standard output.

Global options
Global options affect the operation of tests and actions specified on any
part of the command line. Global options always return true. The -depth
option for example makes find traverse the file system in a depth-first
order.

Positional options
Positional optiona affect only tests or actions which follow them. Posi‐
tional options always return true. The -regextype option for example is
positional, specifying the regular expression dialect for regulat expres‐
sions occurring later on the command line.

Operators
Operators join together the other items within the expression. They include
for example -o (meaning logical OR) and -a (meaning logical AND). Where an
operator is missing, -a is assumed.

If the whole expression contains no actions other than -prune or -print, -print is
performed on all files for which the whole expression is true.

The -delete action also acts like an option (since it implies -depth).

POSITIONAL OPTIONS
Positional options always return true. They affect only tests occurring later on
the command line.

-daystart
Measure times (for -amin, -atime, -cmin, -ctime, -mmin, and -mtime) from the
beginning of today rather than from 24 hours ago. This option only affects
tests which appear later on the command line.

-follow
Deprecated; use the -L option instead. Dereference symbolic links. Implies
-noleaf. The -follow option affects only those tests which appear after it
on the command line. Unless the -H or -L option has been specified, the
position of the -follow option changes the behaviour of the -newer predi‐
cate; any files listed as the argument of -newer will be dereferenced if
they are symbolic links. The same consideration applies to -newerXY,
-anewer and -cnewer. Similarly, the -type predicate will always match
against the type of the file that a symbolic link points to rather than the
link itself. Using -follow causes the -lname and -ilname predicates always
to return false.

-regextype type
Changes the regular expression syntax understood by -regex and -iregex tests
which occur later on the command line. To see which regular expression
types are known, use -regextype help. The Texinfo documentation (see SEE
ALSO) explains the meaning of and differences between the various types of
regular expression.

-warn, -nowarn
Turn warning messages on or off. These warnings apply only to the command
line usage, not to any conditions that find might encounter when it searches
directories. The default behaviour corresponds to -warn if standard input
is a tty, and to -nowarn otherwise. If a warning message relating to com‐
mand-line usage is produced, the exit status of find is not affected. If
the POSIXLY_CORRECT environment variable is set, and -warn is also used, it
is not specified which, if any, warnings will be active.

GLOBAL OPTIONS
Global options always return true. Global options take effect even for tests which
occurr earlier on the command line. To prevent confusion, global options should
specified on the command-line after the list of start points, just before the first
test, positional option or action. If you specify a global option in some other
place, find will issue a warning message explaining that this can be confusing.

The global options occur after the list of start points, and so are not the same
kind of option as -L, for example.

-d A synonym for -depth, for compatibility with FreeBSD, NetBSD, MacOS X and
OpenBSD.

-depth Process each directory's contents before the directory itself. The -delete
action also implies -depth.

-help, --help
Print a summary of the command-line usage of find and exit.

-ignore_readdir_race
Normally, find will emit an error message when it fails to stat a file. If
you give this option and a file is deleted between the time find reads the
name of the file from the directory and the time it tries to stat the file,
no error message will be issued. This also applies to files or directo‐
ries whose names are given on the command line. This option takes effect at
the time the command line is read, which means that you cannot search one
part of the filesystem with this option on and part of it with this option
off (if you need to do that, you will need to issue two find commands
instead, one with the option and one without it).

-maxdepth levels
Descend at most levels (a non-negative integer) levels of directories below
the starting-points. -maxdepth 0
means only apply the tests and actions to the starting-points themselves.

-mindepth levels
Do not apply any tests or actions at levels less than levels (a non-negative
integer). -mindepth 1 means process all files except the starting-points.

-mount Don't descend directories on other filesystems. An alternate name for
-xdev, for compatibility with some other versions of find.

-noignore_readdir_race
Turns off the effect of -ignore_readdir_race.

-noleaf
Do not optimize by assuming that directories contain 2 fewer subdirectories
than their hard link count. This option is needed when searching filesys‐
tems that do not follow the Unix directory-link convention, such as CD-ROM
or MS-DOS filesystems or AFS volume mount points. Each directory on a nor‐
mal Unix filesystem has at least 2 hard links: its name and its `.' entry.
Additionally, its subdirectories (if any) each have a `..' entry linked to
that directory. When find is examining a directory, after it has statted 2
fewer subdirectories than the directory's link count, it knows that the rest
of the entries in the directory are non-directories (`leaf' files in the
directory tree). If only the files' names need to be examined, there is no
need to stat them; this gives a significant increase in search speed.

-version, --version
Print the find version number and exit.

-xautofs
Don't descend directories on autofs filesystems.

-xdev Don't descend directories on other filesystems.

TESTS
Some tests, for example -newerXY and -samefile, allow comparison between the file
currently being examined and some reference file specified on the command line.
When these tests are used, the interpretation of the reference file is determined
by the options -H, -L and -P and any previous -follow, but the reference file is
only examined once, at the time the command line is parsed. If the reference file
cannot be examined (for example, the stat(2) system call fails for it), an error
message is issued, and find exits with a nonzero status.

Numeric arguments can be specified as

+n for greater than n,

-n for less than n,

n for exactly n.

-amin n
File was last accessed n minutes ago.

-anewer file
File was last accessed more recently than file was modified. If file is a
symbolic link and the -H option or the -L option is in effect, the access
time of the file it points to is always used.

-atime n
File was last accessed n*24 hours ago. When find figures out how many
24-hour periods ago the file was last accessed, any fractional part is
ignored, so to match -atime +1, a file has to have been accessed at least
two days ago.

-cmin n
File's status was last changed n minutes ago.

-cnewer file
File's status was last changed more recently than file was modified. If
file is a symbolic link and the -H option or the -L option is in effect, the
status-change time of the file it points to is always used.

-ctime n
File's status was last changed n*24 hours ago. See the comments for -atime
to understand how rounding affects the interpretation of file status change
times.

-empty File is empty and is either a regular file or a directory.

-executable
Matches files which are executable and directories which are searchable (in
a file name resolution sense). This takes into account access control lists
and other permissions artefacts which the -perm test ignores. This test
makes use of the access(2) system call, and so can be fooled by NFS servers
which do UID mapping (or root-squashing), since many systems implement
access(2) in the client's kernel and so cannot make use of the UID mapping
information held on the server. Because this test is based only on the
result of the access(2) system call, there is no guarantee that a file for
which this test succeeds can actually be executed.

-false Always false.

-fstype type
File is on a filesystem of type type. The valid filesystem types vary among
different versions of Unix; an incomplete list of filesystem types that are
accepted on some version of Unix or another is: ufs, 4.2, 4.3, nfs, tmp,
mfs, S51K, S52K. You can use -printf with the %F directive to see the types
of your filesystems.

-gid n File's numeric group ID is n.

-group gname
File belongs to group gname (numeric group ID allowed).

-ilname pattern
Like -lname, but the match is case insensitive. If the -L option or the
-follow option is in effect, this test returns false unless the symbolic
link is broken.

-iname pattern
Like -name, but the match is case insensitive. For example, the patterns
`fo*' and `F??' match the file names `Foo', `FOO', `foo', `fOo', etc. The
pattern `*foo*` will also match a file called '.foobar'.

-inum n
File has inode number n. It is normally easier to use the -samefile test
instead.

-ipath pattern
Like -path. but the match is case insensitive.

-iregex pattern
Like -regex, but the match is case insensitive.

-iwholename pattern
See -ipath. This alternative is less portable than -ipath.

-links n
File has n links.

-lname pattern
File is a symbolic link whose contents match shell pattern pattern. The
metacharacters do not treat `/' or `.' specially. If the -L option or the
-follow option is in effect, this test returns false unless the symbolic
link is broken.

-mmin n
File's data was last modified n minutes ago.

-mtime n
File's data was last modified n*24 hours ago. See the comments for -atime
to understand how rounding affects the interpretation of file modification
times.

-name pattern
Base of file name (the path with the leading directories removed) matches
shell pattern pattern. Because the leading directories are removed, the
file names considered for a match with -name will never include a slash, so
`-name a/b' will never match anything (you probably need to use -path
instead). A warning is issued if you try to do this, unless the environment
variable POSIXLY_CORRECT is set. The metacharacters (`*', `?', and `[]')
match a `.' at the start of the base name (this is a change in findu‐
tils-4.2.2; see section STANDARDS CONFORMANCE below). To ignore a directory
and the files under it, use -prune; see an example in the description of
-path. Braces are not recognised as being special, despite the fact that
some shells including Bash imbue braces with a special meaning in shell pat‐
terns. The filename matching is performed with the use of the fnmatch(3)
library function. Don't forget to enclose the pattern in quotes in order
to protect it from expansion by the shell.

-newer file
File was modified more recently than file. If file is a symbolic link and
the -H option or the -L option is in effect, the modification time of the
file it points to is always used.

-newerXY reference
Succeeds if timestamp X of the file being considered is newer than timestamp
Y of the file reference. The letters X and Y can be any of the following
letters:

a The access time of the file reference
B The birth time of the file reference
c The inode status change time of reference
m The modification time of the file reference
t reference is interpreted directly as a time

Some combinations are invalid; for example, it is invalid for X to be t.
Some combinations are not implemented on all systems; for example B is not
supported on all systems. If an invalid or unsupported combination of XY is
specified, a fatal error results. Time specifications are interpreted as
for the argument to the -d option of GNU date. If you try to use the birth
time of a reference file, and the birth time cannot be determined, a fatal
error message results. If you specify a test which refers to the birth time
of files being examined, this test will fail for any files where the birth
time is unknown.

-nogroup
No group corresponds to file's numeric group ID.

-nouser
No user corresponds to file's numeric user ID.

-path pattern
File name matches shell pattern pattern. The metacharacters do not treat
`/' or `.' specially; so, for example,
find . -path "./sr*sc"
will print an entry for a directory called `./src/misc' (if one exists). To
ignore a whole directory tree, use -prune rather than checking every file in
the tree. For example, to skip the directory `src/emacs' and all files and
directories under it, and print the names of the other files found, do some‐
thing like this:
find . -path ./src/emacs -prune -o -print
Note that the pattern match test applies to the whole file name, starting
from one of the start points named on the command line. It would only make
sense to use an absolute path name here if the relevant start point is also
an absolute path. This means that this command will never match anything:
find bar -path /foo/bar/myfile -print
Find compares the -path argument with the concatenation of a directory name
and the base name of the file it's examining. Since the concatenation will
never end with a slash, -path arguments ending in a slash will match nothing
(except perhaps a start point specified on the command line). The predicate
-path is also supported by HP-UX find and will be in a forthcoming version
of the POSIX standard.

-perm mode
File's permission bits are exactly mode (octal or symbolic). Since an exact
match is required, if you want to use this form for symbolic modes, you may
have to specify a rather complex mode string. For example `-perm g=w' will
only match files which have mode 0020 (that is, ones for which group write
permission is the only permission set). It is more likely that you will
want to use the `/' or `-' forms, for example `-perm -g=w', which matches
any file with group write permission. See the EXAMPLES section for some
illustrative examples.

-perm -mode
All of the permission bits mode are set for the file. Symbolic modes are
accepted in this form, and this is usually the way in which you would want
to use them. You must specify `u', `g' or `o' if you use a symbolic mode.
See the EXAMPLES section for some illustrative examples.

-perm /mode
Any of the permission bits mode are set for the file. Symbolic modes are
accepted in this form. You must specify `u', `g' or `o' if you use a sym‐
bolic mode. See the EXAMPLES section for some illustrative examples. If no
permission bits in mode are set, this test matches any file (the idea here
is to be consistent with the behaviour of -perm -000).

-perm +mode
This is no longer supported (and has been deprecated since 2005). Use -perm
/mode instead.

-readable
Matches files which are readable. This takes into account access control
lists and other permissions artefacts which the -perm test ignores. This
test makes use of the access(2) system call, and so can be fooled by NFS
servers which do UID mapping (or root-squashing), since many systems imple‐
ment access(2) in the client's kernel and so cannot make use of the UID map‐
ping information held on the server.

-regex pattern
File name matches regular expression pattern. This is a match on the whole
path, not a search. For example, to match a file named `./fubar3', you can
use the regular expression `.*bar.' or `.*b.*3', but not `f.*r3'. The regu‐
lar expressions understood by find are by default Emacs Regular Expressions,
but this can be changed with the -regextype option.

-samefile name
File refers to the same inode as name. When -L is in effect, this can
include symbolic links.

-size n[cwbkMG]
File uses n units of space, rounding up. The following suffixes can be
used:

`b' for 512-byte blocks (this is the default if no suffix is used)

`c' for bytes

`w' for two-byte words

`k' for Kilobytes (units of 1024 bytes)

`M' for Megabytes (units of 1048576 bytes)

`G' for Gigabytes (units of 1073741824 bytes)

The size does not count indirect blocks, but it does count blocks in sparse
files that are not actually allocated. Bear in mind that the `%k' and `%b'
format specifiers of -printf handle sparse files differently. The `b' suf‐
fix always denotes 512-byte blocks and never 1 Kilobyte blocks, which is
different to the behaviour of -ls. The + and - prefixes signify greater
than and less than, as usual, but bear in mind that the size is rounded up
to the next unit (so a 1-byte file is not matched by -size -1M).

-true Always true.

-type c
File is of type c:

b block (buffered) special

c character (unbuffered) special

d directory

p named pipe (FIFO)

f regular file

l symbolic link; this is never true if the -L option or the -follow
option is in effect, unless the symbolic link is broken. If you want
to search for symbolic links when -L is in effect, use -xtype.

s socket

D door (Solaris)

-uid n File's numeric user ID is n.

-used n
File was last accessed n days after its status was last changed.

-user uname
File is owned by user uname (numeric user ID allowed).

-wholename pattern
See -path. This alternative is less portable than -path.

-writable
Matches files which are writable. This takes into account access control
lists and other permissions artefacts which the -perm test ignores. This
test makes use of the access(2) system call, and so can be fooled by NFS
servers which do UID mapping (or root-squashing), since many systems imple‐
ment access(2) in the client's kernel and so cannot make use of the UID map‐
ping information held on the server.

-xtype c
The same as -type unless the file is a symbolic link. For symbolic links:
if the -H or -P option was specified, true if the file is a link to a file
of type c; if the -L option has been given, true if c is `l'. In other
words, for symbolic links, -xtype checks the type of the file that -type
does not check.

-context pattern
(SELinux only) Security context of the file matches glob pattern.

ACTIONS
-delete
Delete files; true if removal succeeded. If the removal failed, an error
message is issued. If -delete fails, find's exit status will be nonzero
(when it eventually exits). Use of -delete automatically turns on the
`-depth' option.

Warnings: Don't forget that the find command line is evaluated as an expres‐
sion, so putting -delete first will make find try to delete everything below
the starting points you specified. When testing a find command line that
you later intend to use with -delete, you should explicitly specify -depth
in order to avoid later surprises. Because -delete implies -depth, you can‐
not usefully use -prune and -delete together.

-exec command ;
Execute command; true if 0 status is returned. All following arguments to
find are taken to be arguments to the command until an argument consisting
of `;' is encountered. The string `{}' is replaced by the current file name
being processed everywhere it occurs in the arguments to the command, not
just in arguments where it is alone, as in some versions of find. Both of
these constructions might need to be escaped (with a `\') or quoted to pro‐
tect them from expansion by the shell. See the EXAMPLES section for exam‐
ples of the use of the -exec option. The specified command is run once for
each matched file. The command is executed in the starting directory.
There are unavoidable security problems surrounding use of the -exec action;
you should use the -execdir option instead.

-exec command {} +
This variant of the -exec action runs the specified command on the selected
files, but the command line is built by appending each selected file name at
the end; the total number of invocations of the command will be much less
than the number of matched files. The command line is built in much the
same way that xargs builds its command lines. Only one instance of `{}' is
allowed within the command. The command is executed in the starting direc‐
tory. If any invocation returns a non-zero value as exit status, then find
returns a non-zero exit status. If find encounters an error, this can some‐
times cause an immediate exit, so some pending commands may not be run at
all. This variant of -exec always returns true.

-execdir command ;

-execdir command {} +
Like -exec, but the specified command is run from the subdirectory contain‐
ing the matched file, which is not normally the directory in which you
started find. This a much more secure method for invoking commands, as it
avoids race conditions during resolution of the paths to the matched files.
As with the -exec action, the `+' form of -execdir will build a command line
to process more than one matched file, but any given invocation of command
will only list files that exist in the same subdirectory. If you use this
option, you must ensure that your $PATH environment variable does not refer‐
ence `.'; otherwise, an attacker can run any commands they like by leaving
an appropriately-named file in a directory in which you will run -execdir.
The same applies to having entries in $PATH which are empty or which are not
absolute directory names. If any invocation returns a non-zero value as
exit status, then find returns a non-zero exit status. If find encounters
an error, this can sometimes cause an immediate exit, so some pending com‐
mands may not be run at all. The result of the action depends on whether the
+ or the ; variant is being used; -execdir command {} + always returns true,
while -execdir command {} ; returns true only if command returns 0.

-fls file
True; like -ls but write to file like -fprint. The output file is always
created, even if the predicate is never matched. See the UNUSUAL FILENAMES
section for information about how unusual characters in filenames are han‐
dled.

-fprint file
True; print the full file name into file file. If file does not exist when
find is run, it is created; if it does exist, it is truncated. The file
names `/dev/stdout' and `/dev/stderr' are handled specially; they refer to
the standard output and standard error output, respectively. The output
file is always created, even if the predicate is never matched. See the
UNUSUAL FILENAMES section for information about how unusual characters in
filenames are handled.

-fprint0 file
True; like -print0 but write to file like -fprint. The output file is
always created, even if the predicate is never matched. See the UNUSUAL
FILENAMES section for information about how unusual characters in filenames
are handled.

-fprintf file format
True; like -printf but write to file like -fprint. The output file is
always created, even if the predicate is never matched. See the UNUSUAL
FILENAMES section for information about how unusual characters in filenames
are handled.

-ls True; list current file in ls -dils format on standard output. The block
counts are of 1K blocks, unless the environment variable POSIXLY_CORRECT is
set, in which case 512-byte blocks are used. See the UNUSUAL FILENAMES sec‐
tion for information about how unusual characters in filenames are handled.

-ok command ;
Like -exec but ask the user first. If the user agrees, run the command.
Otherwise just return false. If the command is run, its standard input is
redirected from /dev/null.

The response to the prompt is matched against a pair of regular expressions
to determine if it is an affirmative or negative response. This regular
expression is obtained from the system if the `POSIXLY_CORRECT' environment
variable is set, or otherwise from find's message translations. If the sys‐
tem has no suitable definition, find's own definition will be used. In
either case, the interpretation of the regular expression itself will be
affected by the environment variables 'LC_CTYPE' (character classes) and
'LC_COLLATE' (character ranges and equivalence classes).

-okdir command ;
Like -execdir but ask the user first in the same way as for -ok. If the
user does not agree, just return false. If the command is run, its standard
input is redirected from /dev/null.

-print True; print the full file name on the standard output, followed by a new‐
line. If you are piping the output of find into another program and there
is the faintest possibility that the files which you are searching for might
contain a newline, then you should seriously consider using the -print0
option instead of -print. See the UNUSUAL FILENAMES section for information
about how unusual characters in filenames are handled.

-print0
True; print the full file name on the standard output, followed by a null
character (instead of the newline character that -print uses). This allows
file names that contain newlines or other types of white space to be cor‐
rectly interpreted by programs that process the find output. This option
corresponds to the -0 option of xargs.

-printf format
True; print format on the standard output, interpreting `\' escapes and `%'
directives. Field widths and precisions can be specified as with the
`printf' C function. Please note that many of the fields are printed as %s
rather than %d, and this may mean that flags don't work as you might expect.
This also means that the `-' flag does work (it forces fields to be left-
aligned). Unlike -print, -printf does not add a newline at the end of the
string. The escapes and directives are:

\a Alarm bell.

\b Backspace.

\c Stop printing from this format immediately and flush the output.

\f Form feed.

\n Newline.

\r Carriage return.

\t Horizontal tab.

\v Vertical tab.

\0 ASCII NUL.

\\ A literal backslash (`\').

\NNN The character whose ASCII code is NNN (octal).

A `\' character followed by any other character is treated as an ordinary
character, so they both are printed.

%% A literal percent sign.

%a File's last access time in the format returned by the C `ctime' func‐
tion.

%Ak File's last access time in the format specified by k, which is either
`@' or a directive for the C `strftime' function. The possible val‐
ues for k are listed below; some of them might not be available on
all systems, due to differences in `strftime' between systems.

@ seconds since Jan. 1, 1970, 00:00 GMT, with fractional part.

Time fields:

H hour (00..23)

I hour (01..12)

k hour ( 0..23)

l hour ( 1..12)

M minute (00..59)

p locale's AM or PM

r time, 12-hour (hh:mm:ss [AP]M)

S Second (00.00 .. 61.00). There is a fractional part.

T time, 24-hour (hh:mm:ss)

+ Date and time, separated by `+', for example
`2004-04-28+22:22:05.0'. This is a GNU extension. The time
is given in the current timezone (which may be affected by
setting the TZ environment variable). The seconds field
includes a fractional part.

X locale's time representation (H:M:S)

Z time zone (e.g., EDT), or nothing if no time zone is deter‐
minable

Date fields:

a locale's abbreviated weekday name (Sun..Sat)

A locale's full weekday name, variable length (Sunday..Saturday)

b locale's abbreviated month name (Jan..Dec)

B locale's full month name, variable length (January..December)

c locale's date and time (Sat Nov 04 12:02:33 EST 1989). The
format is the same as for ctime(3) and so to preserve compati‐
bility with that format, there is no fractional part in the
seconds field.

d day of month (01..31)

D date (mm/dd/yy)

h same as b

j day of year (001..366)

m month (01..12)

U week number of year with Sunday as first day of week (00..53)

w day of week (0..6)

W week number of year with Monday as first day of week (00..53)

x locale's date representation (mm/dd/yy)

y last two digits of year (00..99)

Y year (1970...)

%b The amount of disk space used for this file in 512-byte blocks.
Since disk space is allocated in multiples of the filesystem block
size this is usually greater than %s/512, but it can also be smaller
if the file is a sparse file.

%c File's last status change time in the format returned by the C
`ctime' function.

%Ck File's last status change time in the format specified by k, which is
the same as for %A.

%d File's depth in the directory tree; 0 means the file is a starting-
point.

%D The device number on which the file exists (the st_dev field of
struct stat), in decimal.

%f File's name with any leading directories removed (only the last ele‐
ment).

%F Type of the filesystem the file is on; this value can be used for
-fstype.

%g File's group name, or numeric group ID if the group has no name.

%G File's numeric group ID.

%h Leading directories of file's name (all but the last element). If
the file name contains no slashes (since it is in the current direc‐
tory) the %h specifier expands to ".".

%H Starting-point under which file was found.

%i File's inode number (in decimal).

%k The amount of disk space used for this file in 1K blocks. Since disk
space is allocated in multiples of the filesystem block size this is
usually greater than %s/1024, but it can also be smaller if the file
is a sparse file.

%l Object of symbolic link (empty string if file is not a symbolic
link).

%m File's permission bits (in octal). This option uses the `tradi‐
tional' numbers which most Unix implementations use, but if your par‐
ticular implementation uses an unusual ordering of octal permissions
bits, you will see a difference between the actual value of the
file's mode and the output of %m. Normally you will want to have a
leading zero on this number, and to do this, you should use the #
flag (as in, for example, `%#m').

%M File's permissions (in symbolic form, as for ls). This directive is
supported in findutils 4.2.5 and later.

%n Number of hard links to file.

%p File's name.

%P File's name with the name of the starting-point under which it was
found removed.

%s File's size in bytes.

%S File's sparseness. This is calculated as (BLOCKSIZE*st_blocks /
st_size). The exact value you will get for an ordinary file of a
certain length is system-dependent. However, normally sparse files
will have values less than 1.0, and files which use indirect blocks
may have a value which is greater than 1.0. The value used for
BLOCKSIZE is system-dependent, but is usually 512 bytes. If the
file size is zero, the value printed is undefined. On systems which
lack support for st_blocks, a file's sparseness is assumed to be 1.0.

%t File's last modification time in the format returned by the C `ctime'
function.

%Tk File's last modification time in the format specified by k, which is
the same as for %A.

%u File's user name, or numeric user ID if the user has no name.

%U File's numeric user ID.

%y File's type (like in ls -l), U=unknown type (shouldn't happen)

%Y File's type (like %y), plus follow symlinks: L=loop, N=nonexistent

%Z (SELinux only) file's security context.

%{ %[ %(
Reserved for future use.

A `%' character followed by any other character is discarded, but the other
character is printed (don't rely on this, as further format characters may
be introduced). A `%' at the end of the format argument causes undefined
behaviour since there is no following character. In some locales, it may
hide your door keys, while in others it may remove the final page from the
novel you are reading.

The %m and %d directives support the # , 0 and + flags, but the other direc‐
tives do not, even if they print numbers. Numeric directives that do not
support these flags include G, U, b, D, k and n. The `-' format flag is
supported and changes the alignment of a field from right-justified (which
is the default) to left-justified.

See the UNUSUAL FILENAMES section for information about how unusual charac‐
ters in filenames are handled.

-prune True; if the file is a directory, do not descend into it. If -depth is
given, false; no effect. Because -delete implies -depth, you cannot use‐
fully use -prune and -delete together.

-quit Exit immediately. No child processes will be left running, but no more
paths specified on the command line will be processed. For example, find
/tmp/foo /tmp/bar -print -quit will print only /tmp/foo. Any command lines
which have been built up with -execdir ... {} + will be invoked before find
exits. The exit status may or may not be zero, depending on whether an
error has already occurred.

OPERATORS
Listed in order of decreasing precedence:

( expr )
Force precedence. Since parentheses are special to the shell, you will nor‐
mally need to quote them. Many of the examples in this manual page use
backslashes for this purpose: `$...$' instead of `(...)'.

! expr True if expr is false. This character will also usually need protection
from interpretation by the shell.

-not expr
Same as ! expr, but not POSIX compliant.

expr1 expr2
Two expressions in a row are taken to be joined with an implied "and"; expr2
is not evaluated if expr1 is false.

expr1 -a expr2
Same as expr1 expr2.

expr1 -and expr2
Same as expr1 expr2, but not POSIX compliant.

expr1 -o expr2
Or; expr2 is not evaluated if expr1 is true.

expr1 -or expr2
Same as expr1 -o expr2, but not POSIX compliant.

expr1 , expr2
List; both expr1 and expr2 are always evaluated. The value of expr1 is dis‐
carded; the value of the list is the value of expr2. The comma operator can
be useful for searching for several different types of thing, but traversing
the filesystem hierarchy only once. The -fprintf action can be used to list
the various matched items into several different output files.

UNUSUAL FILENAMES
Many of the actions of find result in the printing of data which is under the con‐
trol of other users. This includes file names, sizes, modification times and so
forth. File names are a potential problem since they can contain any character
except `\0' and `/'. Unusual characters in file names can do unexpected and often
undesirable things to your terminal (for example, changing the settings of your
function keys on some terminals). Unusual characters are handled differently by
various actions, as described below.

-print0, -fprint0
Always print the exact filename, unchanged, even if the output is going to a
terminal.

-ls, -fls
Unusual characters are always escaped. White space, backslash, and double
quote characters are printed using C-style escaping (for example `\f',
`\"'). Other unusual characters are printed using an octal escape. Other
printable characters (for -ls and -fls these are the characters between
octal 041 and 0176) are printed as-is.

-printf, -fprintf
If the output is not going to a terminal, it is printed as-is. Otherwise,
the result depends on which directive is in use. The directives %D, %F, %g,
%G, %H, %Y, and %y expand to values which are not under control of files'
owners, and so are printed as-is. The directives %a, %b, %c, %d, %i, %k,
%m, %M, %n, %s, %t, %u and %U have values which are under the control of
files' owners but which cannot be used to send arbitrary data to the termi‐
nal, and so these are printed as-is. The directives %f, %h, %l, %p and %P
are quoted. This quoting is performed in the same way as for GNU ls. This
is not the same quoting mechanism as the one used for -ls and -fls. If you
are able to decide what format to use for the output of find then it is nor‐
mally better to use `\0' as a terminator than to use newline, as file names
can contain white space and newline characters. The setting of the
`LC_CTYPE' environment variable is used to determine which characters need
to be quoted.

-print, -fprint
Quoting is handled in the same way as for -printf and -fprintf. If you are
using find in a script or in a situation where the matched files might have
arbitrary names, you should consider using -print0 instead of -print.

The -ok and -okdir actions print the current filename as-is. This may change in a
future release.

STANDARDS CONFORMANCE
For closest compliance to the POSIX standard, you should set the POSIXLY_CORRECT
environment variable. The following options are specified in the POSIX standard
(IEEE Std 1003.1, 2003 Edition):

-H This option is supported.

-L This option is supported.

-name This option is supported, but POSIX conformance depends on the POSIX confor‐
mance of the system's fnmatch(3) library function. As of findutils-4.2.2,
shell metacharacters (`*', `?' or `[]' for example) will match a leading
`.', because IEEE PASC interpretation 126 requires this. This is a change
from previous versions of findutils.

-type Supported. POSIX specifies `b', `c', `d', `l', `p', `f' and `s'. GNU find
also supports `D', representing a Door, where the OS provides these.

-ok Supported. Interpretation of the response is according to the "yes" and
"no" patterns selected by setting the `LC_MESSAGES' environment variable.
When the `POSIXLY_CORRECT' environment variable is set, these patterns are
taken system's definition of a positive (yes) or negative (no) response.
See the system's documentation for nl_langinfo(3), in particular YESEXPR and
NOEXPR. When `POSIXLY_CORRECT' is not set, the patterns are instead taken
from find's own message catalogue.

-newer Supported. If the file specified is a symbolic link, it is always derefer‐
enced. This is a change from previous behaviour, which used to take the
relevant time from the symbolic link; see the HISTORY section below.

-perm Supported. If the POSIXLY_CORRECT environment variable is not set, some
mode arguments (for example +a+x) which are not valid in POSIX are supported
for backward-compatibility.

Other predicates
The predicates -atime, -ctime, -depth, -group, -links, -mtime, -nogroup,
-nouser, -print, -prune, -size, -user and -xdev `-atime', `-ctime',
`-depth', `-group', `-links', `-mtime', `-nogroup', `-nouser', `-perm',
`-print', `-prune', `-size', `-user' and `-xdev', are all supported.

The POSIX standard specifies parentheses `(', `)', negation `!' and the `and' and
`or' operators ( -a, -o).

All other options, predicates, expressions and so forth are extensions beyond the
POSIX standard. Many of these extensions are not unique to GNU find, however.

The POSIX standard requires that find detects loops:

The find utility shall detect infinite loops; that is, entering a previously
visited directory that is an ancestor of the last file encountered. When it
detects an infinite loop, find shall write a diagnostic message to standard
error and shall either recover its position in the hierarchy or terminate.

GNU find complies with these requirements. The link count of directories which
contain entries which are hard links to an ancestor will often be lower than they
otherwise should be. This can mean that GNU find will sometimes optimise away the
visiting of a subdirectory which is actually a link to an ancestor. Since find
does not actually enter such a subdirectory, it is allowed to avoid emitting a
diagnostic message. Although this behaviour may be somewhat confusing, it is
unlikely that anybody actually depends on this behaviour. If the leaf optimisation
has been turned off with -noleaf, the directory entry will always be examined and
the diagnostic message will be issued where it is appropriate. Symbolic links can‐
not be used to create filesystem cycles as such, but if the -L option or the -fol‐
low option is in use, a diagnostic message is issued when find encounters a loop of
symbolic links. As with loops containing hard links, the leaf optimisation will
often mean that find knows that it doesn't need to call stat() or chdir() on the
symbolic link, so this diagnostic is frequently not necessary.

The -d option is supported for compatibility with various BSD systems, but you
should use the POSIX-compliant option -depth instead.

The POSIXLY_CORRECT environment variable does not affect the behaviour of the
-regex or -iregex tests because those tests aren't specified in the POSIX standard.

ENVIRONMENT VARIABLES
LANG Provides a default value for the internationalization variables that are
unset or null.

LC_ALL If set to a non-empty string value, override the values of all the other
internationalization variables.

LC_COLLATE
The POSIX standard specifies that this variable affects the pattern matching
to be used for the -name option. GNU find uses the fnmatch(3) library
function, and so support for `LC_COLLATE' depends on the system library.
This variable also affects the interpretation of the response to -ok; while
the `LC_MESSAGES' variable selects the actual pattern used to interpret the
response to -ok, the interpretation of any bracket expressions in the pat‐
tern will be affected by `LC_COLLATE'.

LC_CTYPE
This variable affects the treatment of character classes used in regular
expressions and also with the -name test, if the system's fnmatch(3) library
function supports this. This variable also affects the interpretation of
any character classes in the regular expressions used to interpret the
response to the prompt issued by -ok. The `LC_CTYPE' environment variable
will also affect which characters are considered to be unprintable when
filenames are printed; see the section UNUSUAL FILENAMES.

LC_MESSAGES
Determines the locale to be used for internationalised messages. If the
`POSIXLY_CORRECT' environment variable is set, this also determines the
interpretation of the response to the prompt made by the -ok action.

NLSPATH
Determines the location of the internationalisation message catalogues.

PATH Affects the directories which are searched to find the executables invoked
by -exec, -execdir, -ok and -okdir.

POSIXLY_CORRECT
Determines the block size used by -ls and -fls. If POSIXLY_CORRECT is set,
blocks are units of 512 bytes. Otherwise they are units of 1024 bytes.

Setting this variable also turns off warning messages (that is, implies
-nowarn) by default, because POSIX requires that apart from the output for
-ok, all messages printed on stderr are diagnostics and must result in a
non-zero exit status.

When POSIXLY_CORRECT is not set, -perm +zzz is treated just like -perm /zzz
if +zzz is not a valid symbolic mode. When POSIXLY_CORRECT is set, such
constructs are treated as an error.

When POSIXLY_CORRECT is set, the response to the prompt made by the -ok
action is interpreted according to the system's message catalogue, as
opposed to according to find's own message translations.

TZ Affects the time zone used for some of the time-related format directives of
-printf and -fprintf.

EXAMPLES
find /tmp -name core -type f -print | xargs /bin/rm -f

Find files named core in or below the directory /tmp and delete them. Note that
this will work incorrectly if there are any filenames containing newlines, single
or double quotes, or spaces.

find /tmp -name core -type f -print0 | xargs -0 /bin/rm -f

Find files named core in or below the directory /tmp and delete them, processing
filenames in such a way that file or directory names containing single or double
quotes, spaces or newlines are correctly handled. The -name test comes before the
-type test in order to avoid having to call stat(2) on every file.

find . -type f -exec file '{}' \;

Runs `file' on every file in or below the current directory. Notice that the
braces are enclosed in single quote marks to protect them from interpretation as
shell script punctuation. The semicolon is similarly protected by the use of a
backslash, though single quotes could have been used in that case also.

find / $ -perm -4000 -fprintf /root/suid.txt '%#m %u %p\n' $ , \
$ -size +100M -fprintf /root/big.txt '%-10s %p\n' $

Traverse the filesystem just once, listing setuid files and directories into
/root/suid.txt and large files into /root/big.txt.

find $HOME -mtime 0

Search for files in your home directory which have been modified in the last
twenty-four hours. This command works this way because the time since each file
was last modified is divided by 24 hours and any remainder is discarded. That
means that to match -mtime 0, a file will have to have a modification in the past
which is less than 24 hours ago.

find /sbin /usr/sbin -executable \! -readable -print

Search for files which are executable but not readable.

find . -perm 664

Search for files which have read and write permission for their owner, and group,
but which other users can read but not write to. Files which meet these criteria
but have other permissions bits set (for example if someone can execute the file)
will not be matched.

find . -perm -664

Search for files which have read and write permission for their owner and group,
and which other users can read, without regard to the presence of any extra permis‐
sion bits (for example the executable bit). This will match a file which has mode
0777, for example.

find . -perm /222

Search for files which are writable by somebody (their owner, or their group, or
anybody else).

find . -perm /220
find . -perm /u+w,g+w
find . -perm /u=w,g=w

All three of these commands do the same thing, but the first one uses the octal
representation of the file mode, and the other two use the symbolic form. These
commands all search for files which are writable by either their owner or their
group. The files don't have to be writable by both the owner and group to be
matched; either will do.

find . -perm -220
find . -perm -g+w,u+w

Both these commands do the same thing; search for files which are writable by both
their owner and their group.

find . -perm -444 -perm /222 ! -perm /111
find . -perm -a+r -perm /a+w ! -perm /a+x

These two commands both search for files that are readable for everybody ( -perm
-444 or -perm -a+r), have at least one write bit set ( -perm /222 or -perm /a+w)
but are not executable for anybody ( ! -perm /111 and ! -perm /a+x respectively).

cd /source-dir
find . -name .snapshot -prune -o $ \! -name *~ -print0 $|
cpio -pmd0 /dest-dir

This command copies the contents of /source-dir to /dest-dir, but omits files and
directories named .snapshot (and anything in them). It also omits files or direc‐
tories whose name ends in ~, but not their contents. The construct -prune -o $
... -print0 $ is quite common. The idea here is that the expression before -prune
matches things which are to be pruned. However, the -prune action itself returns
true, so the following -o ensures that the right hand side is evaluated only for
those directories which didn't get pruned (the contents of the pruned directories
are not even visited, so their contents are irrelevant). The expression on the
right hand side of the -o is in parentheses only for clarity. It emphasises that
the -print0 action takes place only for things that didn't have -prune applied to
them. Because the default `and' condition between tests binds more tightly than
-o, this is the default anyway, but the parentheses help to show what is going on.

find repo/ -exec test -d {}/.svn \; -or \
-exec test -d {}/.git \; -or -exec test -d {}/CVS \; \
-print -prune

Given the following directory of projects and their associated SCM administrative
directories, perform an efficient search for the projects' roots:

repo/project1/CVS
repo/gnu/project2/.svn
repo/gnu/project3/.svn
repo/gnu/project3/src/.svn
repo/project4/.git

In this example, -prune prevents unnecessary descent into directories that have
already been discovered (for example we do not search project3/src because we
already found project3/.svn), but ensures sibling directories (project2 and
project3) are found.

EXIT STATUS
find exits with status 0 if all files are processed successfully, greater than 0 if
errors occur. This is deliberately a very broad description, but if the return
value is non-zero, you should not rely on the correctness of the results of find.

When some error occurs, find may stop immediately, without completing all the
actions specified. For example, some starting points may not have been examined or
some pending program invocations for -exec ... {} + or -execdir ... {} + may not
have been performed.

SEE ALSO
locate(1), locatedb(5), updatedb(1), xargs(1), chmod(1), fnmatch(3), regex(7),
stat(2), lstat(2), ls(1), printf(3), strftime(3), ctime(3)

The full documentation for find is maintained as a Texinfo manual. If the info and
find programs are properly installed at your site, the command info find should
give you access to the complete manual.

HISTORY
As of findutils-4.2.2, shell metacharacters (`*', `?' or `[]' for example) used in
filename patterns will match a leading `.', because IEEE POSIX interpretation 126
requires this.

As of findutils-4.3.3, -perm /000 now matches all files instead of none.

Nanosecond-resolution timestamps were implemented in findutils-4.3.3.

As of findutils-4.3.11, the -delete action sets find's exit status to a nonzero
value when it fails. However, find will not exit immediately. Previously, find's
exit status was unaffected by the failure of -delete.

Feature Added in Also occurs in
-newerXY 4.3.3 BSD
-D 4.3.1
-O 4.3.1
-readable 4.3.0
-writable 4.3.0
-executable 4.3.0
-regextype 4.2.24
-exec ... + 4.2.12 POSIX
-execdir 4.2.12 BSD
-okdir 4.2.12
-samefile 4.2.11
-H 4.2.5 POSIX
-L 4.2.5 POSIX
-P 4.2.5 BSD
-delete 4.2.3
-quit 4.2.3
-d 4.2.3 BSD
-wholename 4.2.0
-iwholename 4.2.0
-ignore_readdir_race 4.2.0
-fls 4.0
-ilname 3.8
-iname 3.8
-ipath 3.8
-iregex 3.8

The syntax -perm +MODE was removed in findutils-4.5.12, in favour of -perm /MODE.
The +MODE syntax had been deprecated since findutils-4.2.21 which was released in
2005.

This happens because *.c has been expanded by the shell resulting in find actually
receiving a command line like this:

find . -name bigram.c code.c frcode.c locate.c -print

That command is of course not going to work. Instead of doing things this way, you
should enclose the pattern in quotes or escape the wildcard:
$ find . -name '*.c' -print
$ find . -name \*.c -print

BUGS
There are security problems inherent in the behaviour that the POSIX standard spec‐
ifies for find, which therefore cannot be fixed. For example, the -exec action is
inherently insecure, and -execdir should be used instead. Please see Finding Files
for more information.

The environment variable LC_COLLATE has no effect on the -ok action.

The best way to report a bug is to use the form at http://savan‐
nah.gnu.org/bugs/?group=findutils. The reason for this is that you will then be
able to track progress in fixing the problem. Other comments about find(1) and
about the findutils package in general can be sent to the bug-findutils mailing
list. To join the list, send email to bug-findutils-request@gnu.org.

FIND(1)

标签：files,option,will,command,file,linux,文档,find
来源： https://www.cnblogs.com/lnlidawei/p/15922543.html

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